Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging

Transcription

1 Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging Raiko Schulz*, Mia Loccufier, Steven Verstockt, Kurt Stockman, Sofie Van Hoecke ECNDT 2014, Prague October 9th, 2014

2 Table of contents Condition monitoring (CM) of offshore wind turbine drivetrains Passive LWIR for machinery fault detection Test setup Experimental methodology and results Conclusions & outlook Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 2 / 23

3 FACULTY OF ENGINEERING AND CM of offshore wind turbine drivetrains Hi ghs peeds haf t Gear box Hub Nac el l e Bl ades Gener at or Mai ns haf t Mec hani c al br eak Tower Figure: Wind turbine drive train Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 3 / 23

4 CM of offshore wind turbine drivetrains Figure: Main bearings in a wind turbine drive train Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 4 / 23

5 Rolling element bearing failures Figure: Rolling element bearing fault evolution Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 5 / 23

6 Open challenges Real-time condition monitoring Early fault detection Fault localization Fault classification Lifetime estimation & maintenance scheduling Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 6 / 23

7 Passive LWIR for machinery fault detection Tribological drive train components naturally generate heat Passive thermography Early fault detection for relatively low temperatures Long-wave infrared (LWIR) LWIR is insensitive to environmental impacts such as dust or fog Passive LWIR allows non-destructive condition monitoring low VIS NIR SWIR MWIR transmittance LWIR 0.38 μm 0.78 μm 1 μm 3 μm 5 μm 7 μm 14 μm Figure: Infrared spectrum Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 7 / 23

8 Test setup Figure: Test setup Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 8 / 23

9 bearing parts Test setup 1 screw locking 2 rolling element 3 inner raceway 4 cage 5 outer raceway 6 outer ring 7 inner ring 8 inner ring bore 9 single lip seal Figure: 3D scheme of Rexnord ER10K deep groove ball bearing Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 9 / 23

10 Test setup FLIR A655sc specifications array cooling uncooled sensitivity 7.5 to 14 µm accuracy ±1 C resolution 640x480 px pixel pitch 17 µm frame rate 50 Hz standard temperature range -20 to 150 C Table: Specifications for FLIR A655sc thermal infrared camera Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 10 / 23

11 Experimental methodology and results Tests on both healthy and pre-damaged bearings Rotational speed of 1,500 rpm Measurement period of fifty minutes Setup initially being cooled down to ambient temperature Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 11 / 23

12 Experimental methodology and results Separation of rings indicating the single bearing components Instead of absolute temperatures, relative temperatures are discussed in order to reduce environmental impacts Ambient temperature has been measured by thermocouples and used as reference temperature Finally, both frame-wise and trend analysis Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 12 / 23

13 FACULTY OF ENGINEERING AND Physical scheme and temperature profiles Figure: Front view of bearing and shaft, and temperature profile directions Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 13 / 23

14 Temperature profiles Figure: Thermal images of both healthy (left) and faulty (right) bearings with temperature profile lines Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 14 / 23

15 Temperature profiles Figure: Thermal image of bearing with outer raceway fault and increased lower temperature limit Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 15 / 23

16 Temperature profiles relative temperature [ C] outer ring lip seal inner ring shaft inner ring lip seal outer ring diameter [mm] healthy bearing outer raceway fault Figure: Hotspot temperature profiles for both healthy and faulty bearing Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 16 / 23

17 Trend analysis Trend analysis for the single bearing components Relative temperatures are discussed in order to reduce environmental impacts Finally, matching of trend graphs with first order dynamics to determine their time constants Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 17 / 23

18 Trend analysis relative temperature [ C] time [minutes] central shaft outer shaft inner ring and shaft contact central inner ring inner ring and seal contact inner seal outer seal outer ring Figure: Relative temperature trends for healthy bearing Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 18 / 23

19 Trend analysis relative temperature [ C] time [minutes] central shaft outer shaft inner ring and shaft contact central inner ring inner ring and seal contact inner seal outer seal outer ring Figure: Relative temperature trends for bearing with outer raceway fault Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 19 / 23

20 First-order step response relative temperature [ C] time [minutes] trend graph step response Figure: Relative temperature trend and first-order step response for contact surface between inner ring and shaft of healthy bearing Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 20 / 23

21 First-order step response time constants in minutes bearing healthy outer raceway fault housing inner ring and shaft contact Table: Time constants after fifty minutes Definition The time constant of the system response is the time which is required by the step response to reach 63% of its final value. Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 21 / 23

22 Conclusions Potential for fault detection as bearing faults lead to faster temperature increase higher maximum temperatures in steady-state Potential for fault localization Potential for monitoring of fully covered and sealed bearings Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 22 / 23

23 Thank you for your attendance! Contact: Outer Raceway Fault Detection and Localization for Deep Groove Ball Bearings by Using Thermal Imaging 23 / 23